Semi-automatic and fully automatic firearms are well known. Semi-automatic firearms shoot one bullet each time that the trigger is pulled. Fully automatic firearms continue shooting as long as the trigger is pulled and they have not exhausted their ammunition. Fully automatic firearms are typically capable of relatively high rates of fire, i.e., cyclic rates. For example, the M16 and the M4 have a nominal cyclic rate of 700 to 950 rounds per minute.
Because fully automatic firearms are capable of such high cyclic rates, they are prone to a variety of problems. For example, sustained fully automatic fire can result in barrel overheating. Barrel overheating is particularly problematic when high capacity magazines, such as SureFire's 60 round and 100 round magazines, are being used. High capacity magazines allow longer periods of sustained fire since fewer magazine changes are required to fire a given number of rounds. Fewer magazine changes provide less time for the barrel to cool. Thus, the barrel, as well as other parts of the firearm, can be subjected to increased heat.
Often, the ability to keep firing is limited by barrel overheating. When the barrel of a firearm overheats, accuracy of the firearm is substantially reduced. Further overheating of the barrel can result in malfunction of the firearm. For example, cartridges chambered into an overheated barrel can detonate prematurely, i.e., cook off, particularly in closed bolt firearms. If the barrel is overheated sufficiently it can deform, thereby resulting in a catastrophic failure of the firearm.
Even after the barrel has returned to an acceptable operating temperature, the firearm may be unusable. The barrel and/or other components of the firearm may have been permanently damaged. Changing the barrel of a contemporary firearm such as the M16 or M4 takes a substantial amount of time and is not generally performed in the field. When the firearm is unusable due to overheating and while the barrel is being changed, a soldier or police officer cannot shoot the firearm and is thus undesirably vulnerable to attack.
The inability to shoot a firearm can have disastrous consequence in battlefield and police situations. The inability to shoot has resulted in loss of life in such instances. Therefore, it is desirable to provide systems and methods for facilitating the quick change of the barrel of a firearm and for otherwise enhancing the reliability and utility of the firearm, for example.